Rattan Lal just won a quarter of a million dollars for his scientific research on dirt. Or as he prefers to call it, “soil.”
And in fact, soil and money have something in common, says Lal, the newly named 2020 World Food Prize Laureate. Think of the ground as similar a bank account. If you want to improve your bank account balance, you have to deposit more money than you withdraw. The same goes for soil. You have to make deposits to keep it healthy.
The most valuable stuff in there is organic matter content — basically, nutrients such as carbon, nitrogen, and hydrogen that a seed needs to grow into a plant. These nutrients need only be present in small amounts; healthy soil is about four percent organic matter content (the rest is water, bugs and particles of rock).
Unfortunately, most soil around the world does not have enough of these nutrients. Decades of erosion and unsustainable farming practices have depleted the soil, leaving just half a percent of organic matter content. According to the Food and Agriculture Organization of the United Nations, about a third of the planet’s soil is “moderately to highly degraded.” When the nutrients in soil are gone, crop yields are lower and the plants that are grown are less healthy. This is bad news for farmers, who are having a harder time producing enough food to feed an ever-growing population.
Over the course of his 50-year career, Lal, a professor of soil science and the director of the Carbon Management and Sequestration Center at Ohio State University, has pioneered farming techniques that prevent soil from losing these vital nutrients and even put nutrients back into soil. Lal’s approach, which he calls “soil-centric,” not only boosts organic matter content but can also help prevent deforestation, mitigate climate change and increase biodiversity.
Lal’s interest in soil began as a child on his family’s small farm in rural, northwestern India. His family’s lives and livelihoods revolved around maintaining their five-acre plot of land: managing weeds, collecting manure from the cattle and spreading it across the fields, and plowing the land by hand in the 120-degree, pre-monsoon Indian summer.
“I was very familiar with the problems of drought, of dust storms, of low crop yields,” Lal recalls. “I remember my father plowing the fields. That was a very hard job. Those images are still there, of hardship, drudgery. The question was why. Why do you have to have that?”
Those experiences and questions propelled Lal to study agriculture at the Punjab Agricultural University in India and then to receive his Ph.D. in soil science from Ohio State University. Two years after graduating, Lal accepted a position as a soil physicist at the International Institute of Tropical Agriculture, in Ibadan, Nigeria. It was April 1970. The local soils had been depleted of their nutrients, and farmers were struggling to grow food on the land they had, so they were cutting down nearby forests to create more farmland.
Lal set out to fix the problem.
For months, the then 25-year-old Lal studied the soil, observing how crops didn’t grow well in soil that was hot to the touch, how storms washed away huge swaths of dirt, how days after a heavy rain the plants would still dry up and wilt.
At his research institute, Lal cleared a small plot of farmland and planned an experiment. Remembering his childhood burden of plowing his family’s farm and pondering the scientific necessity of the process which was meant to soften the soil and prevent weeds, Lal decided to skip the step altogether, an approach called no-till agriculture, which had, at the time, only been pondered by scientists in literature but never widely practiced or studied.
Lal then covered the land with mulch and plant debris, such as leaves and corn stalks; he reasoned this would keep the soil cooler and prevent heavy rains from washing away the soil’s nutrients. After the harvest season, Lal planted and grew another round of crops, but instead of picking them, he let the plants die. This practice, called crop cover agriculture, worked like a bank loan: The crops borrowed the nutrients as they grew, but those nutrients were returned when the plants decomposed. And because he was locking up these nutrients in cover crops, the rainwater and wind couldn’t carry them away.
Over time, the amount of nutrients in Lal’s plot of land went up. He had proven that you could reuse the same farmland without nutrient loss, thereby eliminating the need to cut down forests, as long as farmers followed the right practices.
Lal traveled across Africa, Asia, Australia and South America repeating his experiments with similar success. Lal’s soil-centric farming techniques were revolutionary. No-till and crop cover farming helped pioneer the then-emerging field of conservation agriculture, which focuses on improving soil health and reducing the environmental impact of farming.
“[Lal] was really the first person to put soil science on the map,” says Marco Ferroni of CGIAR, a global agricultural research group. Lal went on to publish over a thousand scientific papers detailing his research. He also worked with hundreds of scientists and farmers worldwide to adapt these practices to various climates, cultures and economies.
In the late 1970s, Lal and his colleagues realized that this soil-centric approach to farming could do more than just bolster nutrients in the soil. It could help fight climate change.
One of the most important nutrients in soil is carbon, which plants make by consuming carbon dioxide, a greenhouse gas that is a biproduct of burning fossil fuels. Lal had years of experimental data showing that his farming practices increased the amount of carbon in the soil. By allowing crops to grow even in the off-season, farmers create the opportunity for more carbon dioxide to be pulled from the air and stored in the soil as carbon. This process, called carbon sequestration, is the same principle behind large-scale tree-planting efforts.
According to Lal, conservation agriculture alongside other land restoration efforts, such as cleaning up coal mining sites and reforesting land impacted by timber harvesting, could remove two to three billion tons of carbon dioxide from the atmosphere, offsetting approximately 15% of global carbon dioxide emissions — all while making soil healthier. Three United Nations Climate Change Conferences backed Lal’s practices as a way to combat climate change, and in 2007, Lal’s work with the Intergovernmental Panel on Climate Change helped the organization to share the year’s Nobel Prize.
Despite the promise of Lal’s farming practices and other conservation agriculture approaches, only about 25 to 30 percent of farmers practice some version of no-till and crop cover agriculture today. The challenges of implementing Lal’s techniques vary across the globe. The plant debris and mulch that Lal encourages farmers to cover their farmland with can be used to feed cattle in Asia and Africa or, in the US, sold to make ethanol fuel. In order to grow crops in the off-season, farmers have to purchase and plant seeds but won’t reap the benefits of harvesting and selling those crops. Simply put, these practices require the world’s farmers to make investments that will benefit the planet but won’t put any money back in their pockets.
Lal’s solution is for governments to fund farmers who provide “ecosystem services.” At approximately $16 per acre per year, according to Lal’s calculations, that would amount to about $64 billion globally. Although the price tag seems high, several countries have experimented with implementing it on a small scale. “If we expect farmers to do good things for the planet, we should pay them for it,” Lal explains.
Lal believes sustainable agriculture practices are the “win-win-win option” as the world grapples with the urgent challenges of climate change and food scarcity. “My philosophy has always been that the health of soil, plants, animal, people, and the environment is one indivisible,” Lal says.